Search and rescue operations over water bodies has many challenges, not the least of which is that the vessel and/or people being sought can move great distances following their last known location. As such, markers have been developed in an attempt to more quickly locate aircraft, ships, and people following accidents over/in bodies of water. These markers tend to be either electrically based (e.g., battery powered signal transmitters) or optically based (e.g., fluorescent dyes).
Electrically based markers are ideal as long as they continue to operate, but can be rendered unusable if severely damaged by impact or if critical components become wet. Fluorescent dyes show promise as universal markers as they will not be impaired by water contact and can be detected at a relatively great distance in both daylight and night search and rescue operations. Unfortunately, most fluorescent dye systems depend upon the ability of someone to release the dye, which may not be possible if the individual is incapacitated. Moreover, once the dye is released, it can dissipate relatively quickly and if the search is not successful within that limited time window, odds for successful recovery decrease rapidly.
What are needed in the art are markers for use in search and rescue operations over water bodies. More specifically, what are needed are devices that can automatically release a detectable marker into surrounding water over a sustained period of time and that can thereby provide a long lasting detectable trail to the target of the search.